Nuclear detection device especially a gamma-camera type device, with deconvolution filters having an inverse transfer function

Abstract

A nuclear detection device, especially a gamma-camera type device which features deconvolution filters. In a gamma-camera variant, the device includes digital filters for deconvoluting electric measuring signals. A transfer function of these filters is opposite that of a circuit having formed the electric signals. It is then possible to separate any pulses which would overlap. Such a system finds particular application in nuclear physics and in particular in the medical field.

What is claimed is: 
     
       1. A nuclear detection device comprising: detecting means for detecting an incident nuclear radiation, the detecting means having a first transfer function;   at least one fast analog/digital converter for receiving signals output by the detecting means;   at least one digital filter for receiving signals output by the at least one fast analog/digital converter, the at least one digital filter having a second transfer function approximately opposite to the first transfer function of the detecting means;   a digital integration means for integrating signals output by the at least one digital filter; and   a determining means for determining a characteristic of the incident nuclear radiation based on signals output by the digital integration means.   
     
     
       2. The device according to claim 1, wherein the characteristic to be determined by the determining means is a position of the incident nuclear radiation. 
     
     
       3. The device according to claim 2, wherein the detecting means comprises: a film of a scintillator material for receiving the incident nuclear radiation, which is gamma radiation, and for generating luminous radiation signals in response to the received nuclear radiation by scintillation, and   photodetection means disposed opposite the scintillator film for receiving the luminous radiation signals output by the scintillator film; and   wherein the determining means determines a position of the scintillation.   
     
     
       4. The device according to claim 3, wherein the detecting means further comprises sets of weighting resistors receiving signals output by the photodetection means and for generating four electric pulse signals x+, x-, y+, y-, signals x+, x- expressing the position of the scintillation with respect to a first axis X, and signal y+, y- expressing the position of the scintillation with respect to a second axis Y. 
     
     
       5. The device according to claim 4, wherein the at least one fast analog/digital converter comprises four fast analog/digital converters for respectively receiving the four signals x+, x-, y+, y- from the sets of weighting resistors and wherein the digital filter comprises four digital filters connected to the four fast analog/digital converters and wherein the digital integration device comprises four digital integrators. 
     
     
       6. The device according to claim 3, further comprising an image memory display device for displaying a result of the determining means. 
     
     
       7. The device according to claim 1, further comprising: delivering means for delivering a digital signal e(N) representing an energy of the incident nuclear radiation, the delivering means having a third transfer function;   a further digital filter for receiving the digital signal e(N), this further digital filter having a fourth transfer function approximately opposite to the third transfer function of the deliverying means,   a detecting circuit for detecting signals output from the further digital filter; and   a digital integrator connected to the detecting circuit and outputting a signal used for validating the determining means.   
     
     
       8. The device according to claim 7, wherein the detection circuit delivers a signal for validating all the integrators. 
     
     
       9. The device according to any one of claim 3 to 6, wherein the photodetection means comprise photomultipliers. 
     
     
       10. The device according to any one of claim 3 to 6, further comprising a gamma radiation collimator placed in front of the film of scintillator material.